2.8e @ 248fsb Ai7 Pwm 96c!!!

[naughty_guy]

New system spec:
2.8E
Stepping: c0 Batch #: 3408A536 Prod Code: SL79k
Pack Date: 3/30/04
AI7
Corsair TWINX PC3200 Platinum
R9600
Sunny 350W PSU (generic brand) 3.3--28A 5V--35A 12V--17A

FSB: 243
Vcore=1.56V
Vdimm=3.2V
ratio: 1:1
Full load CPU temp: 63
Full load PWM temp: 81
RAM timings: 3-8-4-4
PAT: disabled

MCP600
MCW6002
BIX + 12cm fan
T-line

Currently highest performance setting combination found. Comments welcomed.

[eva2000]

make sure fan is blowing over the mosfet/cap/coil that reports pwm temps as well

keeps things cool

http://www.fileshosts.com/pentium4/D1/abit/AI7/results/3.2EE/HC200/OCZ/PC3500PLAT/2x512/NB667/234-234-2226-AAADD-1.825-3.2-1.65/prime95_5hrs08min_15s.jpg

[freecableguy]

Holy crap! You can almost boil water on those MOSFETs. Do yourself a favor and get some heatsinks attached to those with some thermal epoxy and get a BIG fan on them.

[naughty_guy]

yes it is boiling hot. and yea it is blowing at the right spot. The PWM part you ensquared eva2000 is the temperature sensor for the pwm.

[Kunaak]

do yourselt a bigger favor and sell that chip ASAP, running nearly 1.575 volts on a prescott is like running 1.8 on a northwood.

if it takes that much voltage for such a small OC, I'd say that chip isn't worth it.

[thephenom]

get a 2.8m0 or a 3.0C (used), and I think u would find some more fun without burning up ur house.

[nfin1te]

the voltage feed-in sucks on the AI7.
it is uncapable of overclocking prescott cpus, and even using normal northwood cpus it's rather crappy.

but you should add cooling. :D

[eva2000]

AI7 handles northies fine

http://www.fileshosts.com/pentium4/D1/abit/AI7/results/2.8C_SL6Z5_B542/HC200/kingston/khx3200k2/2x256/pair9/NB800/280-224-2226-SREADD-1.875-3.2-1.65-partialPAT/cpuz_idle.jpg

[naughty_guy]

1. could it be the PWM overheating that is causing instability? Because maybe once I get some more cooling on those mosfets, I can lower the Vcore for a stable rig.

2. is 1.56 for a prescott really too much? Some run 1.525 stock. Or am i wrong?

3. WIll a IC7 MAX3 handle a prescott better than the AI7? If so, by how much?

For now, i opened the case and the PWM temp is around 75-80C.

[naughty_guy]

hopefully i'll be able to get some heatsinks on the mosfets tomorrow. WIll let you guys know how much this chip has left.

btw.. can someone shine some light on my 3 questions above?

thx in advance

[deathstar13]

an ai7 will be smoked in no time with no heatsinks on the mosfets,pll and a fan over the pmw.
an ic7 or max 3 will handle the power delivery better imo yes but still needs sinked up.
1.56v on h20 would be a max and 1.6v with phase change.this of course is what i would suggest for long term running.
and yes this heat issue you have will cause instability.

id guess the chip stopping at 3.5ghz as until you get better cooling it aint going nowhere.

[naughty_guy]

seems like it is the PWM overheating that is casuing the instability I had. I thought it was the CPU, so i keep added volts. That somehow solved the problem but also brought the PWM temp even higher, because it has to deliever more voltage.

How i down the Vcore to 1.52 and it's still stable @ 250, yes 250 as I speak. Hopefully i'll get some heatsinks and put them on tomorrow.

[DMylonas]

With water the 4+Ghz are simple with a Presscott....

"Brwmogazos" has a 3.4E and he "catch" 5.2GHz!!!!

http://www.thelab.gr/showthread.php?s=&threadid=5279&perpage=40&pagenumber=2

Look at the pictures.... :D

[Vryada]

hey, get something to cool it better. the prescotts are hot... i am lucky and i got one that doesnt gets too hot but lots of people had problems when trying to oc a prescott.

[naughty_guy]

yes i'm gonna get sinks to cool the mosfets very soon. Probably this Saturday.

[jinu117]

Heh get the sinks. sidewinder.com carries them. Get the micro sink not mosfet sink (too big).
Slow fan over it. It will easily knock down about 20-30c on ur PWM temp if not more. Mine before all stuff was hitting 80c, now chilling around at 56c tops.

[naughty_guy]

oo.. haha so not only me that has the problem. Your mosfets goes to 80C while running a northy?

Nah, i'm just planning to cut up heatsinks from old P4 heatsinks myself. Already got a fan on it.

[naughty_guy]

thx for all the smart warnign guys. Here are the hs i've cut up from an original p4 hs, and we'll see what good wonder can these babies do.

EDIT: alright it's all done now, i was one of the impatient ones too, i turned it on, feel all those heatsinks getting hot, AND GETTING LOOSE. lol so i turned it down and now just waiting it to cure. Will post back this evening.

Stay tuned

[naughty_guy]

It's ready to rock now!!!! The PWM temperature after adding some heatsink and repositioning a 80mm fan that blows at it dropped a mighty 13-15C!!!! Now it is perfectly stable @ 250FSB (used to be unstable), I'll let it run dual instance of FAH tonight, if all goes well, then I will go higher tomorrow.

What will you guys say a safe temperature and voltage for a prescott? Not 5 year long term use, but I would like it to last around 2 years.

thx

[RootX]

Originally posted by eva2000
AI7 handles northies fine

http://www.fileshosts.com/pentium4/D1/abit/AI7/results/2.8C_SL6Z5_B542/HC200/kingston/khx3200k2/2x256/pair9/NB800/280-224-2226-SREADD-1.875-3.2-1.65-partialPAT/cpuz_idle.jpg

It sure does, :D
http://www.thelab.gr/attachment.php?s=&postid=56861

1.9Vcore.

[naughty_guy]

Dang this isn't too good. Anyway some benchies for now

[naughty_guy]

Any ideas for a higher OC? besides selling the current chip or MB.

EDIT: Somone can help me determine what's a safe temperature and voltage for a prescott?

I'm running 1.566V and 67C on an Abit board (which report higher temps). Is that fine?

[naughty_guy]

someone please help this poor guy out.

[Pha_Q]

those temps are high man. thats why i dont like prescotts. c northwoods are nice, and i think you would be able to go higher than 3.5 with a 2.8c or 3.0c if u got decent ram.

[naughty_guy]

yes i heard before i bought it that they are hot, but i didn't know they are THAT hot under water cooling.

[Creep-DK]

Not all of them are that hot, i got a 2.8E running at 3.8 ghz vcore 1.56, cooled by cheap H20 and my temps are: idle 38-39 C full load 51-52 C. Not 100% stable though but it seems like my problem is the hot mosfets too, will do something bout that tomorrow.
Anyways my cpu is totally stable at 265 fsb.

[naughty_guy]

man... u got so much a better chip than i do then i guess. I'm getting 56C (1.58V) (3.5ghz) full load right now with the case open. Air temp around 25C.

[Creep-DK]

Yeah it looks like it, weird though coz mine is same stepping as yours SL79K C0, which week it is i dunno, havent had the water block off since i got it, anyways mine is running on a IS7-E so our temps should be compareable.

[naughty_guy]

i hafta bump the Vcore to 1.61 to run @ 251-252 FSB.

Can anyone tell me is 1.61 way too high for a pressy?

EDIT:
I'm starting to doubt whether it is my PSU limiting my OC... someone please give me some 2nd opinion. Here is what my 350W PSU is powering, and its rails.

2.8E @ 3.5 with 1.58-1.61V
AI7
Corsair TWINX PC3200 Platinum
R9600
MCP600 water pump
2 HD
1 Floppy
2 Optical
3 moderate power fan
Sunny 350W PSU (generic brand) 3.3--28A 5V--35A 12V--17A

[Creep-DK]

I definately would say your psu is a problem, 17a on the 12v rail isn't much especially when oc'ing a prescott, i bet your vcore drops like mad when your cpu gets put to work. I got a Aspire 520w @ 35a on 12v rail, it's cheap and works very well :)
Anyways some ppl thinks 1.61v is too much others don't, i think your will be able to get it down to like 1.53 or 1.56 if you get a psu with better 12v rail.

[naughty_guy]

Surprisingly, under full loop of 3dmark2k3, my 5v rail is 5.30 with 0.03V of flux; my 12v rail is 12.32 with 0.1v of flux. So i think the rails are pretty good. And the 3.3V is measure through motherboard program @ 3.32 fairly stable throughout.

5, 12v rails are measured using a multimeter on a molex head.

The numbers are quite surprising for a fully loaded comp.

[Creep-DK]

Yep i must say those numbers are pretty surprising, but still i think your psu is your main problem, coz i had exactly the same probs with my old 2.8c that i bought from a friend (had a sucky 300w 16a 12v psu then) he could easily run it at 255 fsb with 1.6 vcore, i had to go to 1.6 just to reach 240 which was my highest stable. Btw 3dmark2k3 isn't the hardest on your cpu, try running some prime95, that should give a better idea if im correct about your psu being too weak :)

PS. a little OT if anyone could tell me the location of the pwn on a IS7-E i would be very happy :D

[naughty_guy]

The PWM i think on the IS7-E are also located around the CPU socket where all the mosfets and capacitors are. Usually right above the CPU socket.

Yep, I guess it is my PSU then. Anybody else has some opinion to share please?

[naughty_guy]

After all the trouble, i settled down with 1:1 ratio, which leaves my CPU @ 3.4ghz, slightly slower clock, but allows full potiental of my PC3200 ram. Comments/suggestions welcomed.

[Creep-DK]

How much vcore at 3.4 ghz ?

[naughty_guy]

As edited in my first post, 1.56V (I think my PSU is defnitely holding me back, just like yours before)

EDIT: What PSU u using? looks like u haf a great OC. Cooling?

[Creep-DK]

I got a 520w aspire psu, its very cheap where i live suppose it is everywhere else too :D
My cooling is kinda sucky lol, an all aluminium cpu block, old waterchill radiator and a homemade 3 liter tank.

[naughty_guy]

wow... with a budget cooling attaining such respectable OC, well done!!

[Creep-DK]

Thx, to be honest it sure did surprise that i could get it over 270 fsb without heat problems :)

[Creep-DK]

Hey naughty_guy expect some serious oc from me at the end of the month, im getting a Vapo PE and a IC7 max3 the 24. Hopefully i will get past 4 ghz :bounces:

[#ball3r]

hey naughty...did you get your cpu from ncix? I live in B.C. also and am having trouble with a 2.8E bought from there :(.

http://www.xtremesystems.org/forums/showthread.php?s=&threadid=40217

[naughty_guy]

you're sure right lol. How did you even guessed that? The best I can do is 252ish FSB with 1.61 Vcore, howver that'll force me to use 5:4 ratio.

Therefore I settled using 243FSB, 1:1 ratio, 1.56Vcore and 3.2Vdimm.